[Notes 12]

1. 15 THE BUSINESS CYCLE CHAPTER [Notes 12]

2. Objectives • After studying this chapter, you will able to • Distinguish among the different theories of the business cycle • Explain the Keynesian and monetarist theories of the business cycle • Explain the new classical and new Keynesian theories of the business cycle • Explain real business cycle theory • Describe the origins of, and the mechanisms at work during, the expansion of the 1990s, the recession of 2001, and the Great Depression

3. Must What Goes Up Always Come Down? • In some ways, the 1990s were like the 1920s: rapid economic growth and unprecedented prosperity. • From 1929 through 1933, real GDP fell 30 percent and the economy entered the Great Depression, which lasted until World War II. • There have been ten recessions since 1945; must the cycle continue?

4. Cycle Patterns, Impulses, and Mechanisms • Business Cycle Patterns • The business cycle is an irregular and nonrepeating up-and-down movement of business activity that takes place around a generally rising trend and that shows great diversity. We call it a cycle, but both the amplitude and the frequency tend to be different each time we move through a cycle. • Table 30.1 in the textbook dates business cycles since 1920 and the magnitude of the fall in real GDP from each peak to trough.

5. Cycle Patterns, Impulses, and Mechanisms • Cycle Impulses and Mechanisms • Cycles can be thought of like the ball in a tennis match, the light of night and day, or a child’s rocking horse. • These cycles differ according to the role of outside force and basic system structure.

6. Cycle Patterns, Impulses, and Mechanisms • In a tennis match, an outside force is applied at each turning point. • In the night and day cycle, no outside force is applied and the cycle results from the underlying structure of the solar system. • On the rocking horse, an outside force must be applied to start the cycle but then the cycle proceeds automatically until it needs another outside force. • The business cycle can be thought of as a combination of all three types of cycles; that is, both outside forces (the “impulse”) and structure (the “mechanism”) are important.

7. Cycle Patterns, Impulses, and Mechanisms • The Central Role of Investment and Capital • All theories of the business cycle agree that investment and the accumulation of capital play a crucial role. • Recessions begin when investment slows and recessions turn into expansions when investment increases. • Investment and capital are crucial parts of cycles, but are not the only important parts.

8. Cycle Patterns, Impulses, and Mechanisms • The AS-AD Model • All business cycle theories can be described in terms of the AS-AD model. • Business cycle theories can be divided into two types: • Aggregate demand theories • “Real business cycle” theory

9. Aggregate Demand Theories of the Business Cycle • Three types of aggregate demand theories will be discussed: • Keynesian • Monetarist • Rational expectations

10. Aggregate Demand Theories of the Business Cycle • Keynesian Theory • The Keynesian theory of the business cycle regards volatile expectations as the main source of business cycle fluctuations. • The volatile – i.e. changing suddenly – expectations result in large swings in investment expenditure, and thus cycles.

11. Aggregate Demand Theories of the Business Cycle • Keynesian Impulse • The impulse in the Keynesian theory is expected future sales and expected future profits. • A change in expected future sales and expected future profits changes investment. • Keynes described these expectations as “animal spirits,” which means that because such expectations are hard to predict, they may change radically in response to a small bit of new information.

12. Aggregate Demand Theories of the Business Cycle • Keynesian Cycle Mechanism • The mechanism of the business cycle is the initial change in investment, which affects aggregate demand, combined with a flat (or nearly so) SAS curve, at least to the left of LAS [when the economy has excess capacity]. • An increase in investment has multiplier effects that shift the AD curve rightward; a decrease has similar multiplier effects that shift the AD curve leftward.

13. Aggregate Demand Theories of the Business Cycle • The asymmetry of money wages [money wages go up easily, but resist reduction] means that leftward shifts of AD lower real GDP but, without some other change, money wages do not fall and so the economy remains in a below full-employment equilibrium. • The Keynesian theory is most like the tennis match, in which cycles are the result of outside forces applied at the turning points.

14. Aggregate Demand Theories of the Business Cycle • Figure 15.1 illustrates a Keynesian recession.

15. Aggregate Demand Theories of the Business Cycle • Figure 15.2 illustrates a Keynesian expansion.

16. Aggregate Demand Theories of the Business Cycle • Monetarist Theory • The monetarist theory of the business cycle regards fluctuations in the quantity of money as the main source of business cycle fluctuations in economic activity. In other words, monetarists tend to believe cycles have their origins in mistakes by central banks. • Monetarist Impulse • The initial impulse is the growth rate of the money supply.

17. Aggregate Demand Theories of the Business Cycle • Monetarist Cycle Mechanism • The mechanism is a change in the monetary growth rate that shifts the AD curve combined with an upward sloping SAS curve. • An increase in the growth rate of the money supply lowers interest rates and the foreign exchange rate, both of which have multiplier effects that shift the AD curve rightward. • A decrease in the monetary growth rate has the opposite effects.

18. Aggregate Demand Theories of the Business Cycle • Money wages are only temporarily sticky, so an increase in aggregate demand eventually raises money wage rates and a decrease in aggregate demand eventually lowers money wage rates. • Rightward shifts in the AD curve cause an initial expansion in real GDP, but money wages rise and the expansion ends as GDP returns to potential GDP. • Decreases in AD are similar: they cause an initial decrease in real GDP, but money wages fall and the recession ends as GDP returns to potential GDP.

19. Aggregate Demand Theories of the Business Cycle • The monetarist theory is most like a rocking horse, in that an initial force is required to set it in motion, but once started the cycle automatically moves to the next phase.

20. Aggregate Demand Theories of the Business Cycle • Figure 15.3 illustrates a monetarist business cycle. • Part (a) shows a recession phase.

21. Aggregate Demand Theories of the Business Cycle • Part (b) shows an expansion phase.

22. Aggregate Demand Theories of the Business Cycle • Rational Expectations Theories • A rational expectation is a forecast based on all the available relevant information. • There are two distinctly different rational expectations theories. • The new classical theory of the business cycle regards unanticipated fluctuations in aggregate demand as the main source of economic fluctuations.

23. Aggregate Demand Theories of the Business Cycle • The new Keynesian theory of the business cycle also regards unanticipated fluctuations in aggregate demand as the main source of economic fluctuations but also leaves room for anticipated fluctuations in aggregate demand to play a role.

24. Aggregate Demand Theories of the Business Cycle • Rational Expectations Impulse • Both rational expectations theories regard unanticipated fluctuations in aggregate demand as the impulse of the business cycle. • But the new Keynesian theory says that workers are locked into long-term contracts, so even though a fluctuation in aggregate demand is anticipated now, if it was unanticipated when the contract was signed, it will create a fluctuation in economic activity.

25. Aggregate Demand Theories of the Business Cycle • Rational Expectations Cycle Mechanisms • The mechanism in both theories stresses that changes in aggregate demand affect the price level and hence the real wage, which then leads firms to alter their levels of employment and production. • In both theories, a recession occurs when a decrease in aggregate demand lowers the price level and thereby raises the real wage rate. • This change causes firms to reduce employment so that unemployment rises.

26. Aggregate Demand Theories of the Business Cycle • In both theories, eventually money wages fall so that the recession ends. • The new classical theory asserts that only unanticipated changes in aggregate demand affect real wages; anticipated changes affect the nominal wage rate and have no effect on real wage rates. • Anticipated changes in aggregate demand have no effect on real GDP, according to the new classicists.

27. Aggregate Demand Theories of the Business Cycle • The new Keynesian theory asserts that long-term labor contracts prevent anticipated changes from always affecting the nominal wage rate, so even if a change is correctly anticipated today, if it was unanticipated when the labor contract was signed, it affects the real wage rate. Hence, both anticipated and unanticipated changes in aggregate demand can affect real GDP. • Both theories are like rocking horses, in which an initial force starts the business cycle but then the fluctuation automatically proceeds to the end of the cycle.

28. Aggregate Demand Theories of the Business Cycle • Figure 15.4 illustrates a rational expectations business cycle. • Part (a) shows a recession.

29. Aggregate Demand Theories of the Business Cycle • Part (b) shows an expansion.

30. Aggregate Demand Theories of the Business Cycle • AS-AD General Theory • All three of these types of business cycle explanations can be thought of as special cases of a general AS-AD theory of the business cycle, in which fluctuations in aggregate demand (and sometimes aggregate supply) cause the business cycle.

31. Real Business Cycle Theory • The real business cycle theory (RBC theory) regards technological change that creates random fluctuations in productivity as the source of the business cycle. • The RBC Impulse • The impulse in RBC theory is the growth rate of productivity that results from technological change. • “Growth accounting” is used to measure the effects of technological change. Growth accounting refers to decomposing growth in GDP into its sources – growth in inputs and technological change.

32. Real Business Cycle Theory • Figure 15.5 illustrates the RBC Impulse over 1971–2001.

33. Real Business Cycle Theory • The RBC Mechanism • Two immediate effects follow from a change in productivity • Investment demand changes • The demand for labor changes

34. Real Business Cycle Theory • Figure 15.6 illustrates the capital and labor markets in a real business cycle recession.

35. Real Business Cycle Theory • A decrease in productivity lowers firms’ profit expectations and decreases both investment demand and the demand for labor.

36. Real Business Cycle Theory • The interest rate falls.

37. Real Business Cycle Theory • The lower real interest rate lowers the return from current work so the supply of labor decreases.

38. Real Business Cycle Theory • Employment falls by a large amount and the real wage rate falls by a small amount.

39. Real Business Cycle Theory • Real GDP and the Price Level • The decrease in productivity shifts the LAS curve leftward (there is no SAS curve in the RBC theory). • The decrease in investment demand shifts the AD curve leftward. • The price level falls and real GDP decreases.

40. Real Business Cycle Theory • Figure 15.7 illustrates the changes in aggregate supply and aggregate demand during a real business cycle recession.

41. Real Business Cycle Theory • What Happened to Money? • Money plays no role in the RBC theory; the theory emphasizes that real variables, not nominal or monetary variables, cause business cycles. Hence the name. • Cycles and Growth • The impulse, or “shock”, that drives the cycle in RBC is the same force that generates economic growth. • RBC concentrates on its short-run consequences; growth theory concentrates on its long-term consequences.

42. Real Business Cycle Theory • Criticisms of Real Business Cycle Theory • Money wages are sticky — a fact ignored by RBC theory. • The intertemporal substitution effect is too weak to shift the labor supply curve by enough to decrease employment with only a small change in the real wage rate. • Technology shocks are an implausible source of business cycle fluctuations and measured technology shocks are correlated with factors that change aggregate demand, so are not good measures of pure aggregate supply shocks.

43. Real Business Cycle Theory • Defense of Real Business Cycle Theory • RBC theory explains both cycles and growth in a unified framework. • RBC theory is consistent with a wide range of microeconomic evidence about labor demand and supply, investment demand, and other data. • The correlation between money and the business cycle can arise from economic activity change causing change in the quantity of money and not vice versa.

44. Real Business Cycle Theory • RBC theory raises the possibility that business cycles are “efficient,” implying that efforts to smooth the business cycle could reduce economic welfare rather than increasing it.

45. Expansion and Recession During the 1990s and 2000s • The U.S. Expansion of the 1990s • The expansion that started in March 1991 lasted 120 months. • The previous all-time record for an expansion was 106 months, which took place in the 1960s.

46. Expansion and Recession During the 1990s and 2000s • Productivity Growth in the Information Age • Massive technological change occurred during the 1990s (computers and related technologies exploded, as did biotechnology). • The technological change created profit opportunities, which increased investment demand. • In turn, the higher capital stock increased aggregate supply.

47. Expansion and Recession During the 1990s and 2000s • Fiscal policy and monetary policy • Fiscal policy was restrained. • As a fraction of GDP, government purchases remained about constant and tax revenues increased, largely as a result of a growing economy. • Monetary policy also was restrained. • The Fed generally kept money supply growth at a relatively slow and steady rate that produced falling inflation and interest rates.

48. Expansion and Recession During the 1990s and 2000s • Aggregate Demand and Aggregate Supply During the Expansion • Figure 15.8 illustrates the changes in aggregate demand and aggregate supply that occurred during the 1990s expansion. • In 1991, there was a small recessionary gap.

49. Expansion and Recession During the 1990s and 2000s • Aggregate demand and long-run aggregate supply both increased. • But aggregate demand increased more than long-run aggregate supply, so both the price level and real GDP increased. • In 2001, the economy was at full employment.

50. Expansion and Recession During the 1990s and 2000s • A Real Business Cycle Expansion Phase • This expansion seems be very similar to those RBC predicts: technological change increases productivity, with the result that labor demand and aggregate supply increase.